7 Decide where in the picture the fourth element from the exercise above should be marked. Read the second part of the article and find out if you are right or not.
Since the 1950’s, cell biology has focused on DNA and its informational features. DNA or deoxyribonucleic acid contains the genetic information and is responsible for heredity. Normally DNA does not exist as a single molecule but a pair of molecules which are tightly wound and form a double spiral. The DNA molecule is very long — when unwound, it measures about five centimetres! Amazing, but these huge molecules are cleverly packed in a tiny nucleus, which can only be seen through an electronic microscope.
The DNA molecule consists of segments. The segments which store the genetic information are called genes. Scientists are still uncertain about the number of genes each person has — the numbers vary from 20,000 up to 100,000! When a new organism is coming into existence, it inherits genes from the parents. These genes determine the physical, physiological and behavioural characteristics of the new living being.
It’s believed that the information stored in genes can be decoded, and scientists are very enthusiastic about cracking the genetic code. It will enable people to know what the would-be organism is going to be like. Ambitious scientists go further -they mean not only prediction, but the possibility of altering the genetic code for medical or other purposes. Their plan sounds both exciting and scary. What will genetic experiments lead us to?
Since the 1950’s, cell biology has focused on DNA and its informational features. DNA or deoxyribonucleic acid contains the genetic information and is responsible for heredity. Normally DNA does not exist as a single molecule but a pair of molecules which are tightly wound and form a double spiral. The DNA molecule is very long — when unwound, it measures about five centimetres! Amazing, but these huge molecules are cleverly packed in a tiny nucleus, which can only be seen through an electronic microscope.
The DNA molecule consists of segments. The segments which store the genetic information are called genes. Scientists are still uncertain about the number of genes each person has — the numbers vary from 20,000 up to 100,000! When a new organism is coming into existence, it inherits genes from the parents. These genes determine the physical, physiological and behavioural characteristics of the new living being.
It’s believed that the information stored in genes can be decoded, and scientists are very enthusiastic about cracking the genetic code. It will enable people to know what the would-be organism is going to be like. Ambitious scientists go further -they mean not only prediction, but the possibility of altering the genetic code for medical or other purposes. Their plan sounds both exciting and scary. What will genetic experiments lead us to?
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